The present invention relates to a safety belt buckle for receiving and locking an insertion tongue, the safety belt buckle comprising a housing with an insertion path that contains a spring-loaded ejector. A latch is connected to the housing and cooperates with a cutout of the insertion tongue and a recess of the housing in the locking position. A slide key which is guided transverse to a plane of movement of the latch is provided for releasing the latch from its locking position. A securing element secures the latch in its locking position and is displaceably arranged within the housing so that it can be moved into a release position for the latch by the slide key. Furthermore, a compensation mass member is provided within the housing and is slidable for compensating acceleration forces acting on the safety belt buckle.
A safety belt buckle of the aforementioned kind is disclosed in German Offenlegungsschrift 35 33 684. When acceleration forces act on this device, the danger exits that the slide key is inserted in the release direction of the latch, which is arranged in a self-opening manner, activating the securing element which forces the latch into its locking position. Therefore, in the known safety belt buckle a compensation mass member is supported in a movable and spring-loaded manner, whereby the mass of the compensation mass member corresponds to the mass of the slide key so that the compensation mass member is able to compensate acceleration forces acting on the slide key.
However, the aforementioned safety belt buckle has the disadvantage that the compensation mass member essentially acts on the slide key and thus secures the securing element only in an indirect manner against opening movements. The design of the safety belt buckle and the arrangement of the compensation mass member are complicated and expensive, and furthermore, it is difficult to adjust the threshold for the activation of the compensation mass with respect to the required compensating force.
It is therefore an object of the present invention to simplify the design of the aforementioned safety belt buckle with respect to the arrangement of the compensation mass member and to directly improve the securing effect of the securing element during shock-like loads of the safety belt buckle.